Pump for liquids



Feb. 25, 1941. I R. H. DICKINSON I 2,232,678"

PUMP FOR LIQUIDS Filed March 17, 1938 4 HI: 'IUM TTORIVEYS Patented res.as, in

new roa trams ichard Harland Dicou, London, England, assignor to FluidTransfer Limited, London, England, a Exit-fish company Applicationhiarch l'i, 1938, Serial No. 196,499

in Great Fa:-

41 Clai. (Cl. 103-75) 1 This invention is for improvements in or relat-,ing to pumps for liquids, and has for its object v to provide animproved construction and arrangement of a pump which is extremelysimple in its mechanical details, and is capable of raising liquidsefiiciently,.e v'en from a depth below the mobile portion of" the pumpgreater than the barometric column, and of delivering it at any'required pressure.

Pumps made according to this invention comprise as their essentialfeatures a submerged inlet pipe provided with a non-return inlet valve,situated as hereinafter described, an outlet pipe, communicating withthe inlet pipe, and means for intermittently applying pressure at theirjunction, which point for convenience is hereinafter referred to as thepressure chamber.

As a result of such pressure the column of liquid above the pressurechamber is set in motion so as to separate, or tend to separate, itfrom. that below the pressure chamber. This pressure also tends tocompress the inlet column and to transfer energy to the inlet part ofthe system, thereby causing expansion and/or extension of the piping,

and to a certain amount, compression of the liquid itself. On theremoval'oi the pressure on the upper surface of the liquid in the inletpart this energy, or a portion thereof, is utilised to raise the liquidin such part, and thereby enable the foot valve to open (even in caseswhere the inlet column is of greater height than the barometric column)and further liquid to be admitted. It is therefore an essential featureof this in- ,vention that the foot valve should be situated at asum'cient distance below the pressurechamber to permit of a considerableamount of energy being stored in the inlet portion of the system, andpreferably this valve is situated at the bottom of the inlet pipe, asany portion of such-pipe below the foot valve is not available forstoring energy.

We also prefer to arrange the outlet pipe, by which we mean that portionof the system which is' above the pressure chamber, so that there is asubstantial headof liquid therein, as thi facilitates the imparting ofenergy to the inlet column, since it enables greater efiective pressureto be developed thereon. In all cases the head of liquid must beadequate to enable sufilcient pressure to be applied to the surface ofthe inlet column so as to transfer thereto the energy necessary to setthis column in upward motion, and thereby enable liquid to enter throughthe foot valve. It is necessary that the pipes forming the inlet part ofthe system, and/or the liquid, should possess sumcient elasticity forstoring the necessary energy, but we have found that with thecomparatively small pumps with which we have experimented up to now theordinary cast iron, steel or earthenware pipes are satisfactory, and wehave also worked with rubber hose.

In order to start the pump it is necessary that it should be primed, i.e., there should be a sumcient column of liquid above the level of thepressure chamber. v

Preferably pressure is applied by means of a piston reciprocating in acylinder which is in free communication with the inlet and deliverypipes.

The invention contemplates the provision of an improved construction andarrangement of pump of the aforesaid v type, in which all valves exceptthe inlet valve are iliminated, andwhich operates on a cycle that isindependent of its speed; it is thereby distinguished from known pumpsof the said type which operate by setting up resonant pressure waves inthe system and also from those which operate on a cycle determined bythe operation of their valves.

In the accompanying drawing,

Figure 1 is a purely diagrammatic illustration of one embodiment of theinvention.

Figure 2 is a similar illustration of a modified arrangement of inletpipe and delivery pipe.

Figure 3 is a similar illustration showing means for controlling thedelivery of the pump, and

Figure 4 is a similar illustration showing the novel pumping systemadapted for transferring liquids in either of two directions.

Like reference characters indicate throughout the drawing. a

Referring first to Figure 1 which shows diagrammatically a pump systemaccording to the like parts present invention in its simplest form, apipe it with the pipe ill, the sole function of this cylinder and pistonbeing to exert pressure intermittently on the contents of the pipe It.It will be seen therefore that many other devices than a cylinder andpiston may be used in its place.

The connection id to the pump cylinder may be situated at any convenientpoint in the length of the pipe II and in thecase of a deep-lift pump,

it may be situated above theheigh't of a barol5 constitutes the inletpipe, and the portion of it between the connection l5 and the deliveryend I4 constitutes the delivery pipe and these names will be used todesignate these two parts hereinafter.

The operation of this pump is as follows: The whole system is primedwith liquid as above described, and preferably the connection J6 andcylinder I! are also fllled with liquid when .the piston I8 is at theouter end of its stroke. .The non-return inlet valve 13 is held closedby the pressure of this column of liquid. When the piston is forcedinwards it exerts a pressure on the liquid in both the inlet anddelivery pipes and since the non-return valve i3 is closed no liquid canescape from the inlet pipe and the liquid in the pipe itself is thussubjected to the full pressure exerted by the piston, and the inlet partof the system with the liquid in it is strained so that the piping isexpanded and the liquid is compressed according to their respectivephysical characteristics.

Simultaneously, the application of the pressure by the piston I'B to theliquid in the delivery pipe causes it to be discharged therethrough, andpreferably the dimensions of this pipe are so selected that the liquidis given a high velocity.

Conveniently, this is effected by employing a' delivery pipe of smalldiameter relatively to the cylinder of the pump.

Where the delivery end I 4 is open, the pressure in the system which canbe generated by the piston [8 depends upon the mass of liquid in thedelivery pipe and the acceleration which is imparted to it, and it isdesirable that this pressure should be high and this is effected byensuring either that there is a large mass in the delivery pipe, or'that it is given a very high velocity, or both.

When the liquid in the delivery pipe has attained itsmaximum velocitythe piston is approaching, or is at, the inner end of its strokedepending .upon the mechanical arrangements used for operating thepiston; if it is driven through a crank and-connecting rod it will havean ap-' proximate harmonic motion and the maximum velocity of the liquidin the delivery pipe wiil occur at or shortly after the middle of theinward stroke of the piston. As soon, however, as the piston slows downor stops, the liquid in the delivery pipe having attained its maximumvelocity will tend to continue in motion, by virtue of its inertia sothat it will separate or tend to separate from the liquid in thecylinder and in the inlet part of the. system. As the pressure on theinlet part of the system is relieved the energy which has been stored inthe inlet .part of the system .is released and the liquid in the inletpart of the system is thereby set in motion towards the delivery pipe,and by being lifted off the inlet valve it relieves the pressure thereonso that an inflow of liquid takes place due to the atmospheric pressureoutside; it will be seen therefore that when the piston is ready tostart on its next inward stroke, some liquid has been discharged throughthe delivery pipe from the open end l4 thereof, some of the liquid inthe inlet pipe has been transfer-red to the delivery pipe and to thepump cylinder, and additional liquid has entered the inlet pipe throughthe non-return valve l3. On the next stroke the cylce of operation isrepeated and this continues so long as the piston is kept in motion sothat liquid is lifted from the supply l2 and delivered from the outletl4.

It will be seen that special advantages arise from this characteristicof the .present invention as for example in the case of pumping a liquidwhich contains a gas in solution. This is troublesome with an ordinarytype of suction pump since the gas tends to come out of solution,whereas in the present system the presence of gas in solution rendersthe liquid more highly compressible so that more energy can be stored init, and the fact that the liquid is subjected to pressure prevents thegas from coming out of solution.

It also lies within the scope of the invention to provide special meansin the inlet part of the system whereby energy may be resilientlyabsorbed, it being appreciated of course that such special means mustalways be capable of withstanding the pressure to which the system maybe subjected in its operation.

In cases where comparatively small lifts are required on the inlet side,the inlet pipe may be made of a suitable resilient material such asstout rubber hose; alternatively, a metal pipe may for example be linedwith rubber-or other resilient material which will easily absorb andreturn energy to the system as required, and it will be appreciated thatthis is useful as for example when pumping corrosive liquids,

The following is an example of an actual construction of a pump used inpractice.

The piston was of 2 ins. diameter and had a 4 ins. stroke and wasactuated by a 1 H. P. motor. The inlet pipe was of mild steel of 1 inchdiameter approximately 66 feet long. The water level was 46 feet belowthe bottom of the pump cylinder which was disposed vertically, and thefoot valve was 20 feet below water level. The delivery pipe was it.long, the first 30 feet being of 1 ins. diameter and the remainder of 3ins. diameter, and the'outlet point of such delivery pipe was 50 feetabove the pressure chamber. When workingat a speed of 340 strokes perminute, a. delivery of 2,400 gallons per hour could be obtained, but thepump could be run at lower speeds absorbing less power.

It will of course be appreciated that the outlet and inlet pipe may formone continuous whole so lon as there are efficient means for apply g theintermittent pressure and that the term "pressure chamber as here usedcovers any arrangement for the application of such pressure.

It is not essential that the piping should be arranged as shown inFigure 1, and Figure 2 shows a different arrangement in which the inletpipe 2| with the non-return valve II is vertical and the delivery pipe22 is horizontal. In this case the cylinder I1 is shown as arrangedvertically and the connection Ii to'the junction between theinlet anddelivery pipes is apparently a continuation of the inlet pipe 2|.Although this arrangement gives the appearance that the'delivery pipe issituated on the inlet side of the pump, it is not so in fact because thedelivery pipe is constituted as before by that part of the pipe betweenthe connection to the cylinder and the open delivery end.

It will be appreciated therefore that any disposition of inlet anddelivery pipes may be used. and the cylinder and piston may be situatedat any point provided it communicates with the junction of the inlet anddelivery pipes so that hereinbefore described and that the 'valves shalleiiectively accommodate such flow.

the pressure can be applied intermittently to them, Preferably, thisconnection will be filled with liquid, as will the cylinder, in orderthat the requisite pressures can be obtained, but in some instances itmay be possible to provide an aircushion between the pump piston and theliquid in the main part of the system. v

It will be appreciated that in the system so far described the onlyvalve present in the system is the automatic non-return inlet valve I3,so that the rate of delivery of fluid by this pump is dependent solelyon the speed of operation of the piston It. If it is desired to providea manual valve control this may be efiected as shown diagrammatically inFigure 3. A manually operated stop valve 23 is shown at the delivery endN of the system; and in order to prevent pressure building up in thesystem when this valve is closed and the piston is left running acylinder 24 having a capacity equal to that of the cylinder i1 isprovided in direct communication with the inlet and delivery pipes, anda piston 25 in this cylinder is provided wth a controlling spring .26normally holding the piston 25 at the inner end of its stroke. Thisspring is of such stiffness that in normal operation of the system itdoes not move, but when the valve'23 is closed the pressure whichdeveloped on the inward movement of the .piston 18 moves the piston 25so that the liquid is merely transferred between the cylinders ii and 25and the pressure on the inlet part of the system isnever relieved sothat no fresh liquid enterslthe system and therefore the pressure doesnot build up.

If the valve 23 is partly opened a restricted delivery is obtained, butthe pressure on the inlet part of the system is not released to the sameextent and therefore a correspondingly reduced intake of liquid throughthe valve l3 takes place.

Sometimes it is required to transfer liquids between two points ineither direction and the pumping system according to the presentinvention lends itself to such an arrangement. This is diagrammaticallyillustrated in Figure 4 in which there are shown two tanks 21, 28. Thepipe 29 between them is connected to apumping cylinder 30 in themannerabove described, and each end of the pipe is provided with anautomatic nonreturn valve 3| and with a stop valve 32 which can beopened or closed at-will, the stop valve opening into the inlet pipeabove the inlet valve 3!. If one valve 32 is closed and the other isopened, the second valve 3! is thereby rendered inoperative and pumpingtakes place, in the manner previously described, from the tank in whichthe stop valve 32' is closed into the tank in which the stop valve isopen. If it is desired to reverse the direction of pumping all that isnecessary is to close the second valve 32 and open the first valve 32;whichever of the nonreturn valves 3! is rendered operative by theclosing of its stop valve determines that that end of the pipeconstitutes the inlet and the other end of the pipe the outlet ordelivery end.

Finally, it is to be pointed out that the drawing accompanying thisspecification is purely diagrammatic and is not intended to limit in anyway the mechanical design or arrangement of the system, and any suitabletypes of valves and any other kind of pump capable of intermittentlyproducing pressure may be used, the only requisite being that asufiicient interval of time should be provided between the pressureimpulses to allow of the transfer of liquid in the manner The presentinvention thus provides an improved construction and arrangement of pumpof the aforesaid type in which all valves except the in et valve areeliminated, and which operates on a cycle that is independent of itsspeed; it is thereby distinguished from known.

pumps of similar types which operate by setting up resonant pressurewaves in the system, and also from those which operate on a cycledetermined by the operation of their valves.

I claim:

1. The method of raising liquids from a depth unrelated to thebarometric column of said liquid, which comprises establishing a columnof liquid in a suitable inherently resilient containing system havingnon-return inlet valve'means adjacent the bottom thereof, establishinganother column of-liquid of considerable length beyond and incommunication with the upper end of said first named column, and in asuitable containing means comprising a free and unobstructed deliverysystem, causing a forward ac celeration of the liquid in the deliverysystem and simultaneously causing a compression impulse in the firstnamed or inlet system by app ying pressure at the point of junction ofsaid two bodies of liquid, thus tending to separate the two bodies ofliquid at said point, storing the energy of the latter impulse in thefirst named or inlet system by the inherent resilience thereof, and

then releasing thestored energy by removing said pressure, and causingthe body of liquid in the inlet system to follow the still moving bodyof liquid into the outlet system, and thus admitting more liquid throughthe inlet valve means to replace the portion of. the liquid which has.moved into said delivery system.

2. A pumping system for liquids comprising an inlet pipe with anon-return inlet valve at its intake end, a' normally open unobstructeddelivery pipe having one end in direct communication with the outlet endof the inlet pipe, the inlet pipe being of considerable length toprovide suflicient inherent resilience and expansion free communicationwith said system at the junction of said inlet and delivery pipes, apiston adapted to reciprocate in said cylinder and means forreciprocating said piston at a rate of speed unrelated to the dimensionsof natural period of vibration of said system but adapted tointermittently apply pressure to the bodies of liquid contained in saidpipes, whereby the liquid in the delivery pipe is moved therethroughduring the application of pressure so that it tends to separate from theliquid in the inlet pipe, and further whereby the pressure'applied tothe inlet part of the system resiliently stores energy uniformlythroughout the whole volume thereof until such energy is released,whereupon the movement of the liquid in the delivery pipe becomesoperative on tli 3 liquid in the inlet pipe to transfer a portionthereof to the delivery pipe and thereby permit the inflow of furtherliquid through the inlet valve, cut-01f means provided in the deliverypipe for turning the flow of liquid absorbing and nullifying only thepressure impulses due to a continued operation of the piston while thecut-on means is closed.

3.'A pumping system for liquids comprising an inlet pipe with anon-return inlet valve at its intake end, a normally open unobstructeddelivery pipe having one end in direct communication with the outlet endof the inlet pipe, the inlet pipe being of'consider'abie length toprovide sufficient inherent-resilience and expansion for the storage ofenergy resulting from intermittently applied pressure, the delivery pipealso being of considerable length to provide a body of liquid ofsuiiicient mass and inertia to ensure the production of adequatepressure on the liquid in the inlet pipe to store said energy and toprovide sufficient momentum to exert a pull upon the body of liquid inthe inlet pipe, a cylinder in free communication with said system at theJunction of said inlet and delivery pipes, a piston adapted toreciprocate in said cylinder and means for reciprocating said piston ata rate of speed unrelated to the dimensions or natural period ofvibration of said system but adapted to intermittently apply pressure tothe bodies of liquid contained in said pipes, whereby the liquid in thedelivery pipe is moved there- 'through during the application ofpressure so the inlet pipe to transfer a portion thereof to the.delivery pipe and thereby permit the inflow of further liquid throughthe inlet valve, cutof! means provided in the delivery pipe for turningthe flow ofliquid on or ofl as the need quires without stoppinatheoperation of said piston, a chamber inthe system adjacent said cylinderand piston, and a spring-pressed piston in said chamber for absorbingand nullifying only the pressure impulses due to the continued,

operation of the pressure applying piston while bration of said systembut adapted to intermitinlet valve, said delivery pipe and said inletpipe aasaera said cut-off means is closed, said spring being ofsufficient stiffness that in normal operation, when said delivery pipeis open and unobstructed, the spring pressed piston does not move.

4. A pumping system for liquids comprising an I inlet pipe with anon-return inlet valve at its intake end, and a normally openunobstructed delivery pipe having one end in direct communication withthe outlet end of the inlet pipe, the inlet pipe being of considerablelength to provide sufficient inherent resilience and expansion for thestorage of energy resulting from intermittently applied pressure, thedelivery pipe also being of considerable length to provide a body ofliquid of sufficient mass and inertia to ensure the 1 production ofadequate pressure on the liquid in the inlet pipe to store said energyand to provide suillcient momentum to exert a pull upon the body ofliquid in the inlet pipe, a cylinder in free communication with saidsystem at the Junction 20 of said inlet and delivery pipes.a pistonadapted to reciprocate in said cylinder and means for reciprocating saidpiston at a rate of speed unrelated to the dimensions or natural periodof vitently apply pressure to the bodies of liquid contained in saidpipes, whereby the liquid in the delivery pipe is moved therethroughduring the application of pressure so that it .tends to separate fromthe liquid in the inlet pipe, and further whereby the pressureapplied tothe inlet part of the system resiliently stores energy uniformlythroughout the whole volume thereof until such energy is released.whereupon the movement of the liquid in the delivery pipe becomesoperative 85 on the liquid in the inlet pipe to transfer a portionthereof to the delivery pipe and thereby permit the inilow of furtherliquid through the each being adapted to. be placed in communica- 40tion with a body of liquid and provided with branched ends, one of thebranches of each of said ends being provided with a non-return valve andthe other branch being fitted with a manually controlled valve,rendering the pipes 45 interchangeable in function to effect transfer ofliquid in either direction.

RICHARD HARLAND mcxmson.

